1. Field of the Invention
The present invention relates to a circuit for controlling current switching in multiple inductive loads, particularly in windings of step motors.
2. Prior Art
Circuits of this type are known in the prior art which use, besides a switching switch for each winding, also an adjustment switch for each winding or each group of windings, each adjustment switch being controlled by its own comparator circuit (PWM loop) driven by its own measurement or sense resistor for the current in that particular winding.
In order to reduce the complexity of such switching control circuits, the use of a single adjustment switch, controlled by a single comparator circuit which is in turn driven by a single sense resistor, arranged in series to all the loads, is known. This simplified circuit, though it avoids the duplication of the PWM control loop, has however the disadvantage that it does not allow the independent adjustment of the current in the two windings, since the overlap of the feed phases of two loads can give rise to mutual influences among the loads, with redistribution of the related currents.